Fix compilation errors

Author: alexandear

src/cmd/compile/internal/ssa/fmahash_test.go

@@ -6,7 +6,6 @@ package ssa_test
 
 import (
 	"internal/testenv"
-	"os"
 	"path/filepath"
 	"regexp"
 	"runtime"

src/cmd/compile/internal/test/fixedbugs_test.go

@@ -61,7 +61,7 @@ func TestIssue16214(t *testing.T) {
 	dir := t.TempDir()
 
 	src := filepath.Join(dir, "x.go")
-	err = os.WriteFile(src, []byte(issue16214src), 0644)
+	err := os.WriteFile(src, []byte(issue16214src), 0644)
 	if err != nil {
 		t.Fatalf("could not write file: %v", err)
 	}

src/cmd/compile/internal/test/ssa_test.go

@@ -34,7 +34,7 @@ func runGenTest(t *testing.T, filename, tmpname string, ev ...string) {
 	}
 	// Write stdout into a temporary file
 	rungo := filepath.Join(t.TempDir(), "run.go")
-	ok = os.WriteFile(rungo, stdout.Bytes(), 0600)
+	ok := os.WriteFile(rungo, stdout.Bytes(), 0600)
 	if ok != nil {
 		t.Fatalf("Failed to create temporary file " + rungo)
 	}